Tags » ecology

Ask 20 gardeners, and you’ll get 40 or more answers on what they consider signs of spring. One of the most common answers, though, will probably be Pussy Willow.

Salix, the Willow family, claims more than 400 members, with a range from the tropics all the way up to being the last woody plant before you are stumbling across the Arctic Circle. Many kinds are native to western China, including the magnificent but weak-wooded Weeping Willow, but North America claims her share as well, about 75 varieties. Pussy Willow is one of these, although there are several willows with that name.

Go to your local garden center, and you’ll probably find, well, you probably won’t find pussy willow at all. Garden centers have a hard time selling very early or very late bloomers, like pussy willow or Witch hazel. Both bloom before most garden centers this far north are even open, and, during the regular growing season, these wonderful shrubs probably wouldn’t even catch your eye.

Should you happen upon one, though, probably in the sale bin, odds are it is a Salix caprea, a European Pussy willow also know as Goat Willow. Native from Europe to northeast Asia and northern Iran, it is nearly identical to our native species, Salix discolor. Our native form is more susceptible to canker, and have deeper brown branches and a nearly bluish white underside to the leaves, but it is the canker scaring plant propagators from growing the native species.

Pussy willow (both) reach about 15-25 feet high, and about 12-15′ in width. Native to wet, moist areas, they are frequently seen in marshes, wetlands, and on the edges of rivers and ponds. The ‘pussies’ we are familar with in kindergarten are male catkins, flowers with inconspicuous or, like Salix, no petals. While most catkins are designed for wind pollination, the Willows are known for insect pollination. Perhaps the non-showiness of the catkins is forgivable in the wild, as nothing else is in bloom, competing for the insects to visit them. For you pollinators among us, they are high-sugar flowers. At any rate, they are easy enough to force in a vase starting in February for the spring-desperate.

In the wild, Pussy Willow is an important source of food for browsing animals, such as deer and moose, although not the most palatable (who asks?). Duck and other waterfowl feed on the catkins in the early spring, while mice and other rodents can be found eating the stems in the winter.

Majorie Harris, in Botanica North America, writes of the Pussy Willow, and references a somewhat sketchy web site for the legend of how Pussy Willows got their name. It’s a Polish legend, and involves a sad, crying cat next to a river, whose kittens had fallen into while chasing Butterflies,as kids and kitts are likely to do. Hearing their cries, the Willow trees next to the banks swept down, arching into the river and allowing the kittens to cling to their branches, when they were safely brought to shore. Every spring since, the willow sprouts tiny fur-like buds at the tips of their branches in remembrance.

We have some Pussy Willows at Middlebury, but I had to do some thinking to remember where. While there undoubltalby some wild native species along Bi-Hall Road or the wetlands next to the Johnson Parking lot, the best species on campus proper are probably right next to Atwater Dining Hall, on the south side, where they were planted in the ditch that runs along there as part of the storm water mediation.

I’m very (very) pleased write that Middlebury College has been named a Tree Campus for 2010, culminating work started in January of last year by the students in my Trees and the Urban Forest Winter Term class. Special thanks goes to two students in particular, Chelsea Ward-Waller and Hilary Platt, for being the driving force behind the application process, and for being strong advocates of our urban forest on campus.

I’ll quote from the letter we received-

The Tree Campus USA program is an initiative that sprang from a partnership between the Arbor Day Foundation and Toyota MotorNorth America, Inc., to foster the development of the next generation of Tree Stewards. The program is designed to award national recognition to college campuses and the leaders of their surrounding communities for promoting healthy urban forest management and engaging the3 campus community in environmental stewardship.

As you already know, trees are a vital component of the infrastructure in campus landscaping, providing environmental and economical benefits. Trees in urban areas, and especially on campuses, reduce the heat island effect caused by pavement and buildings. Leaves filter the air we breather by removing dust and other particles. Properly placed trees create a welcoming environment that makes students, administration,and alumni want to be a part of the campus.

Last year there were 74 Tree Campuses across the country,and this year there are 114. Middlebury is the only campus in Vermont that is a Tree Campus, and one of only two in New England. The older program, Tree City USA, has over 3400 communities, with 8 in Vermont, including Burlington and Rutland. We all can take great pride in our trees and campus landscape, and I enjoy being part of a team that places as much value as we do on our campus environment.

The standards to become a Tree Campus are designed to create a sustainable plan to care for and manage campus trees, and to provide opportunities to engage and educate college students and community members in tree planting, benefits of trees, and in Best Management practices. To be eligible for Tree Campus USA recognition, schools must meet five core standards of tree care and community engagement: Establish a campus tree advisory committee, evidence of a campus tree-care plan, verification of dedicated annual expenditures on the campus tree-care plan, involvement in an Arbor Day observance, and a service-learning project aimed at engaging the student body in sustainable efforts. Collaboration is encouraged-the program is a platform for students, faculty, staff, and community members to team up and learn from one another about the benefits of trees on college campuses. Ensures true sustainability of the urban forest by joining forces with the broader forest community.

Our service learning project was a high point in the entire process. Another group of students in the Winter Term tree class worked on a complete Street Tree plan for an area in Middlebury known as Buttolph Acres. This included an inventory of existing trees, recommended locations and varieties, as well as tree planting specifications. The students also used a computer model known as iTree to estimate what the potential carbon sequestration, storm water abatement, and pollution control the tree planting would yield in 25 and 50 years. The work they put into this is amazing-I highly recommend downloading it ( Buttolph Acres Proposal ) and reading it.

A couple of storms ago, I caught myself absentmindedly sticking our most important snow fighting tool into my pocket, and it occurred to me I’d left it out of the list of techniques and equipment I’ve written about in the past. Yes, for some storms, the most important tool in our kit seems to be the lowly putty knife. I prefer an inch and half blade myself.

I was introduced to this my first winter at Middlebury, during the Valentine’s day storm of 2007. The roads were impassable- I’d tried with a friend in a four wheel drive truck, and we’d turned around and went back to the college to spend the night. This was no ordinary storm, but a a blizzard, so strong we couldn’t keep up with it, either by shovel, tractor, or plow. The most important work of the night remained, though, so we broke into teams of two or three, shovels and putty knives in hand, and trudged from building to building, closing doors.

A plumber told me Middlebury has 110 buildings. I asked him how many exterior doors were on campus, and got a look like I’d lost my mind. Fire codes dictate at least two per building, and some many, many more, so let’s say there is 500. Most of these buildings are heated centrally with steam, from the Service Building. The operators in there work wonders, 24/7, heating the entire campus. Ever had snow block your main door at your house, preventing it from closing? Even if you don’t notice immediately, I bet you quickly figure it out as the draft quickly goes through the house. Some storms seem block doors better than others. Now imagine if even a couple of doors on campus are like that. The magicians in the heating plant notice. Now imagine those storms where even 10% of the doors are stuck part way open. The steam can’t compete,alarms in the plant go off, and precious steam and heat literally goes out the door.

So we go out, putty knives in hand, cleaning door thresholds, making sure the door is re-sealed against the building. The knives scrape the snow from the threshold, and from the underside of the door. It builds up against the door frame as well. If you’re really unfortunate, or in the right storm, hot air from the building is melting the snow in the way, and it re-freezes to rock hard ice.

We’ll gladly do the shoveling, plowing, and salting. Save us some time, though, and close the door behind you. What, did you grow up in a barn? Snow stuck in the threshold? Grab a knife from the dining hall if you have to, I won’t tell Aunt Des.

While doing a post on the Sustainable Sites Initiative for the Atwater Landscape contest blog Turf Battle I’d remembered I also wanted to write about a homeowner version of this document called Landscape for Life. I first read about this project at the wonderful Garden Rant blog, then immediately went to read the document. I’d been following the work of the Sustainable Sites inititive for a while, and am over-joyed to see a less ‘industrial’ application.

Like the Sustainable Sites website, the Landscape for Life website is a great resource in an of itself, but the true reading is found in the large document, available for download. Highly recommended winter reading for your inner gardener.

I’ve been reading quite a bit this fall in various newspapers, web sites, etc. about the science of leaf change, and I thought, well, heck, there goes another blog post. I don’t see the sense to retread ground others are covering.

By now, you’ve probably read that leaf color changes by the shortening of day-length light triggers the tree to begin shutting down the leaves, and that chlorophyll breaks down, and sugar is absorbing into the tree. In a nutshell, the veins connecting the leaf to the tree are closed (abscission layer), and once this is complete the leaf falls.

Weather does play a part in leaf color, and in the color you see in the hills as you visit your children on parent’s weekend here (Hi parents! Your kids are doing fine. They want more money.) Many articles have talked about warm weather delaying fall, cool nights are good, drought bad. It’s easy to understand, though, if you think of it in terms of plant health.

A happy, healthy tree in a good growing season will more than likely have pretty spectacular colors. The factors responsible for bad fall color aren’t good for the tree health either. Drought is bad for fall color, and also bad for the trees. Southern Vermont this year had a pretty bad late summer drought, and when I was on route 4 a week or so ago near Woodstock the leaves were terrible, turning brown and falling off, rather than turning nice colors. Here at Middlebury it’s been a dry September, and then the recent rain storms came at just the right time, and the leaves held on long enough to turn well. Warm fall days and cool nights? Good for sugar production, and the breaking down of chlorophyll in the active leaf. A late spring or a severe summer drought can delay fall color-the tree holding on to it’s leaves as long as possible, storing as much energy as it can before winter.

Another leaf color fact plant geeks have probably noticed is called the Leaf Wave Model. An article at the University of Georgia discusses this: Peak color is an opinion. Different trees turn at different times, and in differing colors. Yellows dominate early, then oranges as both later trees turn, as well as some yellow leaves becoming more orange. Finally reds dominate the landscape, with accompanying orange. Browns come last, generally in oaks. The leaves in Vermont are spectacular because of the forest cover types found here, yellow Ash, orange and red maples, along with splashes of green from Pine and Spruce. By paying careful attention to the mountains in the fall you can watch this leaf color wave happen.

Some other reading I’ve been doing this fall was about the color red, something I’ve never thought about. An interesting question for botanists has been “Why red?”. As chlorophyll disappears from the leaf, the other colors emerge, such as yellows and oranges provided by Carotenoids. Red, though, is expressed through Anthocyanin, but is not found in a leaf, and must be produced. The question, therefore, becomes why would a plant be producing a compound, expending energy, at a time in it’s life cycle when it is trying to store and conserve? There are two schools of thought, and probably both are correct, some for some plants, some for others.

One theory is that anthocyanin is produced in trees in nitrogen poor soils. In some varieties of trees, as the green chlorophyll breaks down, the leaves are vulnerable to bright sunlight, and this sunlight breaks down the produced sugars, thereby not being absorbed back into the tree as energy storage. The red pigmentation acts like a barrier from the sunlight, allowing the tree to absorb more of the sugars it has produced. Nitrogen poor soils means the tree would have produced less sugars, being weaker growing, so more red pigmentation would conserve more of the valuable food.

The other theory is one of coevolution, that red leaves are a signal to insects as a repellent, a red warning signal to the insects attempting to use the tree as an overwintering site. A study has shown this in aphids and apple trees, that wild apple leaves turn red in the fall, and suffer less aphid predation.

Well, we mowed the no-mow again (loving the oxymoron), as it was due for its spring knockdown. Like I’ve seen in quite a few farmers fields this year, it actually wasn’t a great grass year-the clovers, alfalfas, and wildflowers seem to have been able to keep pace with the spring flush of grass growth this year. We do an intitial mowing in June (early July this year, rain) to prevent long grass from being availible for deer tick egg laying, as well as giving the wildflowers a fair shot at competing against the grass. Look around Addison County, at many of the hay fields. The second cut of hay is the attractive one, the one where the alfalfa and clover really stand up, while the grass plays second fiddle. Hopefully, it will be the same in our no-mow zones with wildflowers. This year, though, the wildflowers stood out with the grass, and some early ones had started to bloom. They’ll re-bloom, even after being mown.

Observant people will have also noticed that we slightly expanded some of the no-mow areas this spring. Facilities Services, in concert with the Master Plan committee, identified some areas next to existing no-mow locations that needn’t be mowed lawn. The insight of the Master Plan committee was great to watch. With a wonderful eye for design, they expanded no-mow almost right to the front door of Bi-Hall, further shrinking what we are beginning to call Bicentennial Park, making the park like area smaller, but more readable and usable. The same effect was done up by Hadley-Milliken-Kelly-Lang, bringing the no-mow area closer to the row of dorms, making a park like space for what we are now calling Ross Commons surronded by no-mow meadow. There is a bonfire pit in the middle of the commons now, as well as a volleyball net.

There’s a wonderful article, not availible online, sadly, in the May issue of Landscape Architecture that I’ve recently read, entitled “Graduating To Green”, by Mark Hough, ASLA. It starts “The traditional American campus landscape, captured most vividly by an image of open lawns with mature canopy trees, is one of our most established, celebrated, and significant landscape typologies and is, in the 21st century, at a crossroads.” The article is very interesting, and longer than I have time to write about on a beautiful summer evening, but maybe in the next rainstorm…

My most depressing year at the University of Vermont would have been my junior year. All plant and soil science majors took Plant Pathology that year, two semesters worth. For all of you non-science plant geeks, plant pathology deals with diseases of plants-basically anything except insects. Virus, fungi, bacteria, even abiotic problems were addressed. After a year of learing the various ways plants die, I remember thinking about the hopelessness of it all, wondering how on earth plants even existed.

Insect pest management was the previous year. Insects, while a pain, can very often be sprayed, attacked by other bugs, or even crop rotated away. But most of plant pathology? Hopeless. At best, they are “controlled”, like most fungicides, at worst, well, here’s a list of plants if you have to replant that may not get that disease. No magical sprays, potions, or elixirs to help you along. Often the best defense against many of these problems is simply a good offense-a healthy thriving plant will suffer some little indignities here and there, but will fight on.

The recent spate of warm and wet weather has Verticillium Wilt rearing its nasty little head around. I’ve gotten several emails about it recently, and am expecting more. Verticillium Wilt is a soil borne fungus that enters the roots, then both produces toxins and spreads spores throughout the xylem (water tissues) of the plant. The plant, in a bit of idiotic self defense, uses various compounds to plug the xylem further, ostensibly to stop the spread of the fungus, but further restricting water movement inside. The name wilt is a descriptive, as the first symptom typically seen is the last, as the leaves wilt and die from lack of water.

In fruit trees, the fungus is called Black Heart, commonly seen in Apricots, but is also seen in many types of plants, such as potatoes, tomatoes, mint, and many types of trees and shrubs. The fungi, Verticillium albo-atrum or V. dahliae, can persist in the soil for up to 15 years, forming small black resting structures activated when roots grow near them.

On campus, Verticillium wilt is evident on some older plantings of lilacs, like on the picture below. This particular clump is near Battell, on the wetter, or beach, side. Lilacs don’t like wet feet (roots) to begin with, and this may help bring about the fungus.

Lilacs at Battell

Verticillium symptoms on Lilac

Another victim of Verticillium seems to be a Catalpa, know by my kids as the Green Bean tree, for the size seed pods it produces. Spectacular in flower, this tree was the subject of my first Twitter picture about a month ago. (Are you following Middland on Twitter? I’m having a blast posting pictures of plants in bloom around campus, I’m at http://twitter.com/middland.)

Verticillium wilt in Catalpa

The location is directly across from Emma Willard, blocking one of the special sightlines at Middlebury, that of the view from the front of Emma Willard looking up towards Old Chapel. While I mourn the loss of all trees, more than one person has lamented the unfortunate planting location of this tree, wishing it were elsewhere. This loss is particularly wrenching for me, as I watched it come down with this disease last year, but then watched it leaf and flower out again this spring. Thinking Verticillium more quickly virulent, I had false hope this spring, and now know better. Fortunately, the next nearest tree is a birch, resistant to Verticillium, so this loss should be confined to a single tree.

The poison parsnip is starting to bloom on roadsides, and, being one of those plants I get asked about (and emailed about), I thought I’d fill you in on the nastiness.

Poison parsnip, Pastinaca sativa, is actually Parsnip, the root vegetable. As a vegetable, it was popular in colonial times, as it matures under a very short season, and tastes best after the cold set in. Potatoes became more popular, and parsnip escaped cultivation, and has plagued us since. Related to carrots, they haunted my childhood, not only for an ingredient in pot roast, but an unfortunate nickname through grade school. I bet I would like them now, but I just can’t bring myself to try them.

The poison comes from a chemical in the plant sap called psoralen, which reacts with the human skin to cause (ready for this?) phytophotodermatitis. In a nutshell, the sap reacts with UV sunlight, and causes mild to in some cases quite severe burns. I’ll speak from experience here-a mild case can cause red skin, like a steam burn from your tea kettle. I had full second degree burns on all exposed parts of my legs one year, blisters from shorts to socks. Oh yeah, I was just a poster child for horticulture that summer. The blisters healed after a couple of weeks, but the dark reddish brown blotches stayed for the better part of a year.

The sap is not an oil, unlike poison ivy, so it won’t linger on your clothes, pets, lawn mowers, etc. Being phytotoxic, one must come in contact with the sap in the sun in order to get the burn. When dealing with parsnip, I pick cloudy or even rainy days. It is also safe to brush up against, unlike poison ivy, as the plant does not seem to exude sap from unbroken leaves or stems.

The plant is a biennial-a rosette of leaves the first year, and flower stalks the second. (Parsnip in the store is a one year root). I find this makes eradication a little difficult. Biennials are hell-bent on flowering in their second year-if they don’t, what’s the point to life? So cut down too early, and they form many smaller flowers, and therefore more seeds, than left untouched. The best time to mow seems to be right after they flower, but before they have set seed, like you can fool mother nature that way. Unfortunately, roadside mowing seems to coincide with an earlier mowing, followed by a later mowing spreading the ripe seeds around.

It thrives on roadsides, and other poor growing locations, because the rosettes in the first year are poor competitors, and can’t keep up with a healthy stand of vegetation, such as grass. This is actually the best control method, growing better plants to choke out the parsnip. Other control methods go all medieval, by digging, ripping, pulling,repeated mowing, or just plain cursing the plant out of exisitence. Seeds of parsnip are viable in the soil for up to four years, so vigilance is required. A little herbicide does wonders, if you are so inclined.

Wild parsnip can be found on parts of campus, but not on campus proper. It is along the road down by the recycle center, in such a large patch to make control nearly impossible. Thanks to a timely email from Peter Ryan, there is none in the no-mow zones. His eyes are better than mine. If anyone else in blog-land sees a single plant or two creeping up on campus, let us know. Here’s some pictures taken today along Bi-Hall Road of a couple of plants I found. It’s best to recognize your enemy.

A final reminder to join us, 3:00, on the McCullough Plaza for a tree walk around campus, followed by a tree planting by Bicentennial Hall. Come learn about the trees around us, and make your mark on Middlebury by planting something you’ll watch grow for the rest of your life.
As part of her class project in the Trees and The Urban Forest winter term class, Laura Budd took the tree inventory of the Middlebury College Campus and ran it through iTree, modeling software that quantifies the benefits of a urban tree population. Today seems like an appropriate time to remind everyone of what our campus trees do for our environment.
2.75 million gallons of Stormwater intercepted

270,000 lbs of carbon sequestered yearly, 616,000 lbs sequestered and avoided, and 5.36 million lbs stored in total

I had dreams of guest posting on the great Middlebury Trailrunner, inspired by his post on Snake Mountain (the wildflower in his post is a Hepatica, by the way) . I was going to go for a run up the back side of Snake Mountain, the side where our house is located, taking pictures the whole way of plant life.

Well, I’m not that much of a runner. My reason for running is simply running away from middle age, and besides, the plant life is too distracting, and I’m not sure I want to share the less popular trail up Snake Mountain with everyone. So, the run I was thinking about turned into a much needed and great hike with Nancy and Molly the stillhyperpuppyeventhoughshe’salmostayearold. While not on campus, I still feel like I should share what we saw, though, as this is one of my favorite times of year in the plant world, the quick flash in the pan of the spring ephemerals.

Spring Ephemerals are plants that complete an entire life cycle early in the spring, before the upper tree canopy leafs out. An unknown Wikipedia author writes about “excess light” in the early spring, but after a long Vermont winter we know better. Light can be held in dearth, but the glorious spring rays are to be cherished, not called out as vain and excessive. Imagine the evolutionary trick-sprouting, flowering, reproducing, and storing of energy for the next year all within the light and cold of early spring. What a strategy.

This is Spring Beauty, Claytonia virginica -an apt way to start some pictures. Grows from an underground tuber like a potato, and was used as a food source by native Americans and early settlers.

Wild Oats, or Sessile-leaved Bellwort, Uvularia sessilifolia . A common bellwort, and maybe not technically ephemeral, but pretty nonetheless.

Another Bellwort, the Large Flowered, Uvularia grandiflora .

Hepatica, Hepatica americana , named for the supposed resemblance of the leaves to the shape of the liver. Can be seen in blue, white, or pink flowers.

One of the grand queens in the spring ephemeral world, the Large Flowered Trillium, Trillium grandiflorum .

Personal favorite here, Wake Robin, or Purple Trillium, Trillium erectum. Probably the most common trillium in the northeast, and known for it’s foul scent, which it uses to attract carrion flies for pollination. The smell is such that early herbalists used the plant to treat gangrene, since plants were used to cure the ailments they resembled.

Trout Lily, Erythronium americanum. Very common in the woods lately, and named for the leaf pattern resembling the fish.

Dutchman’s Breeches (best name ever), Dicentra cucullaria. Perennial gardeners will quickly see the resemblance to Bleeding Heart, another Dicentra. Flowers are pollinated by early bumblebees, as honeybees don’t have a long enough proboscis to gather nectar.

Bloodroot, Sanguinaria canadensis. So early blooming, the flowers are self pollinating, just to be on the safe side. The name comes from a dye that can be made from the roots, and was probably the ink used for the Scarlet “A” on the forehead of adulterers. There are some great patches of this in Ridgeline. The plant is myrmecochorous, ant-dependent, as it’s seeds attract the insect which then moves them around and buries them.

Early Meadow Rue, Thalictrum dioicum.

Some Wild Ginger I found in a tree stump, Asarum canadense. Strange and kinda ugly brown flowers thankfully hidden beneath the foliage-ant pollinated.

Mouse Ear Chickweed, Cerastium vulgatum. This was on the top of the mountain by the concrete platform, which makes sense seeing as it is an escaped European plant. Now a lawn weed, but reportedly edible leaves once boiled like other greens.

American Fly Honeysuckle, Lonicera canadensis. Not an ephemeral, but a woody plant along the trail edge.

Bluets, Houstonia caerulea. Another plant found up by the concrete platform, native to fields and open woods.

Early Saxifrage, Saxifraga virginiensis. Feel free to let me know if I’ve mis-identifed this one-I hadn’t brought the wildflower book with me on the hike, and have been identifying from pictures. This was a great find, and a bear to identify. Round Leafed Yellow Violet, Viola rotundifolia. the only stemless yellow violet, with flowers and leaves on separate stalks.